The disposal of old or reclaimed office waste paper is a serious ecological problem. Office waste paper, in general, can include materials such as newsprint, magazine stock, colored ledgers, file stock, xerographic paper, computer printouts, laser printed material, and the like. White office waste, on the other hand, is normally considered to include xerographic paper, laser printed paper, white ledger stock, computer printouts and the like.
The recycling of old or reclaimed white office waste has been limited in the past due to its low strength characteristics. White office waste, due to bleaching, has a lesser strength than virgin unbleached Kraft pulp and if the reclaimed white office waste is repulped, the repulping will further reduce the fiber length and adversely effect the tear strength of the repulped white office waste. Moreover, white office waste contains generally about 8% to 9% of fillers, such as clay or calcium carbonate, as well as quantities of ink and toners. If retained in the pulp, these additives seriously detract from the physical properties of the reclaimed white office waste. On the other hand, removal of the additives is an expensive and time consuming process.
As a further problem, a substantial proportion of white office waste contains calcium carbonate as a filler. Without removal of calcium carbonate, repulped white office waste cannot be used in an acid papermaking process, because the acidic components will react with the calcium carbonate to form calcium sulfate which will deposit in the papermaking machine and adversely effect the papermaking process.
Because of these shortcomings, reclaimed white office waste has been considered unacceptable for use in a paperboard product having high strength requirements, such as linerboard, and reclaimed white office waste has seen only limited use as core stock for products such as paper core stock, roofing felt, cereal box board, and the like.